B&S long recordnumber dilemma

I have some confusion about my assignment. It's probably something not to worry about, but I just need to get it off my chest.

The Data class that needs to implement the DBAccess interface has all methods take a long parameter for the record number. I.e. lockRecord(long), readRecord(long) etc..

Now, I've read a lot on this forum about caching and storing things like deleted records in List objects, but the problem there is that you can't call the get method with the record number, as the recNo is a long. Of course you can cast the long to an int, but what if the whole database exceeds the Integer.MAX value?

Long answer: Do not worry. There are so many reasons to ignore this, few of them are 1. Only a few OS can create database file that can contains "Integer.MAX" no. of records with specified schema. 2. You dont have to cache all deleted record in cache list. Otherwise the cache list will become array of record, right? 3. You can (and should) specified any limitation of you program in you choice document.